1. Field of the Invention
The present invention is related to a door lock, and more particularly to a door lock which is convenient to adjust for installing properly.
2. Description of Related Art
Referring to FIGS. 9 and 10, a conventional door lock is composed of a core (91) received in a cylinder (90), a latch (92), a guard plate (93), a back cover (94), and a knob (95).
The cylinder (90), located at an exterior surface of a door (97), is mounted in a lock bole (971) defined through the door (97). The core (91) is received in the cylinder (90). The latch (92) is received in a latch hole (972) laterally defined in the door (97) and in communication with the lock bole (971). A faceplate (96) is mounted at a sidewall of the door (97), and the latch (92) can extend out from the faceplate (96). The guard plate (93) is provided in the lock hole (971) and at an interior surface of the door (97). Two first screws (932), respectively extending through two first holes (931) in the guard plate (93), are engaged in the cylinder (90). The guard plate (93) is provided with a flat finger (911) extending through the latch (92) and into the core (91). The back cover (94) is mounted outside the guard plate (93) by two second screws (943) respectively extending through two second holes (942) in the back cover (94) and two third holes (933) in the guard plate (93) and engaged in the cylinder (90). The knob (95) is rotatably mounted in a fourth hole (941) in the back cover (94), and the finger (931) is received in the knob (95).
Therefore, turning the knob (95) can turn the core (91) and move the latch (92) by means of the finger (931) to lock/unlock the door.
However, it is difficult to install the lock properly in one time, and the movement of the latch (92) will not be smooth when it is in an improper status, so that adjustment is often needed and may involve repeated trial and error. Referring to FIG. 11, during the adjustment, because the first and second screws (932, 943) are engaged in the cylinder (90) through the guard plate (93) and the back cover (94) respectively, the second screws (943) must be first disengaged to detach the back cover (94), and then the first screws (932) can be loosened for adjusting the guard plate (93). Thus, it is very inconvenient to attempt to adjust the lock. Furthermore, the installed door lock does not have a nice appearance because heads of the second screws (943) exposed from the back cover (94) can be seen.
Therefore, the invention provides a door lock to mitigate and/or obviate the aforementioned problems.